Question: Simplify. Rewrite the expression in the form $9^n$. $(9^{-3})(9^{12})=$
Answer: Recall that $x^n\cdot x^m=x^{n+m}$. $\begin{aligned} (9^{-3})(9^{12})&= 9^{-3+12} \\\\ &= 9^{9} \end{aligned}$